I'd still say that in terms of 100% FPS gaming, you wouldn't even need to spend that much for a K/Q. I'd just get a Sennheiser HD598 or PC360 which are about as good, cheaper, and doesn't need the power that the AKGs do. The HD598 is the best alternative to the K701 I've heard, and easier to use.
The 70x is overkill for 100% fps gaming IMO. You don't gain much if any advantage in soundstage and positioning over the Sennheisers or Audio Technicas. What you gain is a more enjoyable sound signature.